} CAS: Teachers - Sustainable Fishing in the Philippines

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Post-Visit Activity: Sustainable Fishing in the Philippines


In this game, students will learn that unsustainable fishing risks depletion and extinction of fish populations, and brainstorm solutions to protect coral reefs and fish for future generations.


In this game, students will:
  1. learn that unsustainable fishing risks depletion and extinction of fish populations.
  2. learn that some unsustainable fishing practices directly damage coral reefs.
  3. brainstorm solutions to protect coral reefs and fish for future generations.


  • two or three bags of popped, plain popcorn (amount depends on class size)
  • small paper cups (1 per student)
  • large paper plates (1 per group)
  • spoons (1 per group)
  • straws (1 per student)
  • watch (for timing the activity)
  • Fishing Log (1 per student)


  • sustainable: meets the needs of the present without compromising the ability of future generations to meet their own needs
  • extinction: when the last individual of a particular species dies
  • bycatch: unwanted marine creatures that are caught in the nets while fishing for another species
  • Tragedy of the Commons: a metaphor dealing with the overexploitation of resources in an area where there is not clear ownership, showing that unrestricted access to a common and finite resource ultimately dooms the resource through over-exploitation



Remind students of their trip to the California Academy of Sciences’ Philippine coral reef exhibit. Tell students that they are going to be fishers in the Philippines and will explore the sustainability of fishing practices. Ask them what sustainability means. To do something sustainably means meeting the needs of people who live now without limiting the ability of people in the future to meet their own needs. This relates to fishing because some of the ways that people currently fish are not sustainable, such as blast fishing and cyanide fishing. These practices destroy habitat, deplete fish populations, and might even lead to the extinction of a species. All of these impacts of fishing limit the ability of future fishers to catch fish.


  1. Explain the game rules:
    • Each student will be a “fisher” whose livelihood depends on catching fish.
    • Each piece of popcorn represents a reef fish.
    • Each fisher must catch at least two fish in each round to survive to the next fishing season.
    • When the fishing season begins, students must hold their hands behind their backs and use the “fishing rod” (straw) to suck “fish” (pieces of popcorn) from the “ocean” (plate) and deposit them into their “boat” (cup).
    • The fish remaining in the ocean after each fishing season represent the reproductive population, and thus one new fish will be added for every fish left in the ocean (plate).
    • After each round, fishers must record their catch in their Fishing Log.
  2. Divide the class into groups of three or four students and have them come up with a name for the coral reef where they fish.
  3. Give each group one plate and each student one cup, one straw, and one copy of the Fishing Log.
  4. Put 30 popcorn pieces on each group’s plate. These are the fish that inhabit their coral reef.
  5. Remind students that all fishers fish at the same time and must keep their hands behind their backs and wait for a signal to start fishing.
  6. Give students 20 seconds for the first “season” of fishing. Note: You can change the time allotted for each season to get the required effect. For example, if students are not depleting their stocks fast enough, you may increase the “season” to 30 seconds or if they are depleting the stocks too fast, you can decrease the time.
  7. After the first round, have each fisher count his or her catch (fish in their cup), the total bycatch for the table (dropped before reaching the cup), and the total fish left in the ocean (plate). Have them record the data in their Fishing Log. Note: Bycatch is any fish (or other creature) that is unintentionally wasted. In the game, a “fish” that leaves the ocean but is not placed into the “boat” is considered bycatch and cannot be put back into the ocean or counted as catch.
  8. In order to survive to the next fishing season, fishers must catch at least two fish. Fishers who did not catch the minimum amount must sit out for the following round.
  9. Add one new fish for every fish left on the plate, explaining that the fish reproduced in between the seasons.
  10. Play a second round and have students record catches on the Fishing Log.
  11. For the third round, tell students that some fishers have decided to use explosives and/or cyanide to increase their catch. Give a spoon to a few fishers from each group. Use of the spoon represents the blast fishing or the cyanide fishing because a fisher can just scoop up the fish that have been stunned.
  12. Continue playing more rounds until one group runs out of fish. Note: If students are not depleting their stocks fast enough, you may give all fishers spoons.
  13. When one group runs out of fish, ask them what they would do in the real world if they caught all of the fish who inhabited their reef and the surrounding waters. (One option is to switch to a different profession, but another option is to move to another area to fish.) Allow students to “invade” other groups when their coral reef is depleted, but don’t tell them that they can do this beforehand. Fishers may either go as a group or they may disperse separately to other reefs.
  14. Repeat fishing, recording, and replenishing fish stocks until all (or most) groups fish out their reefs. The Fishing Log allows for up to six seasons.
  15. Conduct a discussion about the concept of sustainability. If any group did not completely deplete their fish discuss why this happened (less people fishing, etc.) Ask why sustainability might be an important goal for a community and why it might be difficult to achieve that goal. Have each group of students brainstorm ways that they might have made the fisheries more sustainable. Some possible ways are catch limits (a certain number of popcorn pieces), marine reserves (an area of the plate where fishing is not allowed), bans against blast fishing and cyanide fishing (no use of spoons).
  16. Have each group decide on a plan to make their fishery more sustainable.
  17. Conduct another six rounds (or less) of fishing, using the sustainability plans that the students developed. Because students know how to play, these rounds will go faster. Have students record their new season catches and compare them to the trend seen in the previous seasons.
  18. Have students finish filling out their Fishing Log and answer the question, “Was your group successful in making fishing sustainable?”


Ask students what happened when they used cyanide and blast fishing (scooped up fish with their spoons). It was much easier to capture lots of fish and the fish populations declined much quicker. Remind students that these ways of fishing also damage coral reefs. Tell the students some of the ways that Filipinos have been working to preserve Philippine reefs (see teacher background section.) Then, discuss ways in which everyone can help make fishing more sustainable.

  • If you have an aquarium, know where your fish come from and make sure they were captured or grown in a sustainable way.
  • Most of the fish we eat in California don’t come from coral reefs, but there are still more sustainable and less sustainable fish choices. Pay attention to the fish you buy at the store or select from a restaurant menu.
  • Investigate where the fish comes from, and how it was caught.
  • Use the Monterey Bay Seafood Watch guide to help you choose fish that are Best Choices.
  • If you can’t find the answers, ask! You can help create a market for sustainable fishing by increasing demand for these options.
  • Educate others about the importance of sustainable fishing and coral reef conservation.



California Content Standards

Grade Three

Life Sciences

  • 3c. Students know living things cause changes in the environment in which they live: some of these changes are detrimental to the organism or other organisms, and some are beneficial.
  • 3d. Students know when the environment changes, some plants and animals survive and reproduce; others die or move to new locations.

Investigation and Experimentation

  • 5c. Use numerical data in describing and comparing objects, events, and measurements.

Grade Four

Life Sciences

  • 2b. Students know producers and consumers (herbivores, carnivores, omnivores, and decomposers) are related in food chains and food webs and may compete with each other for resources in an ecosystem.

Grade Six

Earth Sciences

  • 6b. Students know different natural energy and material resources, including air, soil, rocks, minerals, petroleum, fresh water, wildlife, and forests, and know how to classify them as renewable or nonrenewable.

Grade Seven

Life Sciences

  • 3e. Students know that extinction of a species occurs when the environment changes and the adaptive characteristics of a species are insufficient for its survival.



The strikingly colorful coral reef display at the California Academy of Sciences is a Philippine coral reef. The Philippines are considered the marine and coastal biodiversity center of the world. The coral reefs in this part of the world are some of the most diverse, but also some of the most threatened. Human impacts such as pollution, climate change, development, and unsustainable fishing practices have damaged these reefs.

Luckily, Filipinos have been working hard to preserve local marine ecosystems. Through the delivery of educational programs, the implementation of sustainable fishing practices, and the establishment of marine parks and reserves, Filipinos are committed to preserving their reefs. The success of these preservation strategies is important for the coral reefs themselves, the community of organisms that inhabits the reefs, the tourists that enjoy these waters, and the Filipino people. Coral reefs in the Philippines offer very important services to local people, providing food, sources of income, and protection from storms.

The struggle to preserve coral reefs is extremely important in the Philippines because of the incredible marine diversity and the high degree of threat, but conserving coral reefs is a critical issue all around the world. The very same issues facing Philippine reefs endanger reefs all over the world. Because reefs all over the world are threatened, now is a critical time for coral reef conservation. In this activity, we will concentrate on one particular threat to coral reef ecosystems: unsustainable fishing.

Although there are many unsustainable and destructive fishing practices, two of the most harmful practices in the Philippines are blast fishing and cyanide fishing. Blast fishing or dynamite fishing uses explosives to stun or kill creatures that live on the reef. This practice allows fishers to harvest a lot of fish at one time with a relatively simple method, but also causes a lot of destruction. The explosions can cause huge craters in the coral resulting in coral death, slower re-growth of coral, and destruction of fish populations. The practice has been used for centuries. Although blast fishing is used all over the globe, it is particularly pervasive in Southeast Asia.

The practice of cyanide fishing uses the toxin cyanide to stun fish, which makes it easier to collect them. The cyanide damages coral reefs because it stresses the coral polyps’ symbiotic algae, zooxanthellae. The coral loose their zooxanthellae, which can be fatal to the coral. Cyanide also damages non-target fish, many invertebrates, eggs, larvae, and microorganisms. Further damage is caused when fishers use hammers to break the reef in order to retrieve fish that have retreated away from the cyanide into the crevices and cracks of the coral reef. Fish populations are diminished both because of the quantity of fish caught and because of the associated habitat destruction. Cyanide fishing was first used in the Philippines in 1962, primarily for the live fish aquarium trade, but the practice has become widespread and is now used throughout Southeast Asia to supply live reef fish to aquariums and restaurants.

Blast fishing and cyanide fishing result in damage to coral reefs and to fish populations. They can decrease the reproductive population of fish and thus decrease the amount of fish available in subsequent years. These practices can also contribute to the extinction of a population or an entire species of fish or coral. Although these impacts affect fishers negatively, individual fishers have no incentive to protect fish for future years because there’s no guarantee that someone else will not catch those fish. Because fish are a shared resource, each fisher tries to catch as many fish as possible despite the un-sustainability of such practices. This scenario is known as the Tragedy of the Commons.

Even though individual fishers don’t necessarily have incentive to conserve, the damage done by these unsustainable fishing practices can be mitigated. Many nations have taken a first step by passing laws that prohibit destructive fishing practices. Some places have implemented strategies such as regulating technology and establishing marine reserves. Although cyanide fishing and blast fishing are illegal in most places, governments are looking into better enforcement and detection strategies. In order to preserve fisheries and coral reefs we need to work together to implement sustainable fishing practices.

In this exercise, students will gain first hand experience with how destructive fishing practices such as blast fishing and cyanide fishing are unsustainable. They will also brainstorm ideas about how to make fishing more sustainable and prevent a Tragedy of the Commons scenario in the future.


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